Several different tools and techniques are available for planning and controlling the quality of a project. The extent to which these tools are used is determined by the project complexity and the quality management program in use by the client.
The following represents the quality planning tools available to the project manager.
Cost-benefit analysis is looking at how much your quality activities will cost versus how much you will gain from doing them. The costs are easy to measure; the effort and resources it takes to do them are just like any other task on your schedule. Since quality activities don’t actually produce a product, it is sometimes harder for people to measure the benefit. The main benefits are less reworking, higher productivity and efficiency, and more satisfaction from both the team and the customer.
Benchmarking means using the results of quality planning on other projects to set goals for your own. You might find that the last project in your company had 20% fewer defects than the one before it. You should want to learn from a project like that and put in practice any of the ideas they used to make such a great improvement. Benchmarks can give you some reference points for judging your own project before you even start the work.
Design of experiments is the list of all the kinds of tests you are going to run on your product. It might list all the kinds of test procedures you’ll do, the approaches you’ll take, and even the tests themselves. (In the software world, this is called test planning.)
Cost of quality is what you get when you add up the cost of all the prevention and inspection activities you are going to do on your project. It doesn’t just include the testing. It includes any time spent writing standards, reviewing documents, meeting to analyze the root causes of defects, reworking to fix the defects once they’re found by the team: in other words, absolutely everything you do to ensure quality on the project. Cost of quality can be a good number to check to determine whether your project is doing well or having trouble. Say your company tracks the cost of quality on all of its projects; then you could tell if you are spending more or less than has been spent on other projects to get your project up to quality standards.
Control charts can be used to define acceptable limits. If some of the functions of a project are repetitive, statistical process controls can be used to identify trends and keep the processes within control limits. Part of the planning for controlling the quality of repetitive processes is to determine what the control limits are and how the process will be sampled.
Cause-and-effect diagrams can help in discovering problems. When control charts indicate an assignable cause for a variation, it is not always easy to identify the cause of a problem. Discussions that are intended to discover the cause can be facilitated using a cause-and-effect or fishbone diagram where participants are encouraged to identify possible causes of a defect.
Example: Diagramming Quality Problems
A small manufacturing firm tries to identify the assignable causes to variations in its manufacturing line. They assemble a team that identifies six possibilities, as shown in the fishbone diagram in Figure 14.5 Cause-and-Effect (Fishbone) Diagram .
Each branch of the diagram can be expanded to break down a category into more specific items. An engineer and an electrician work on one of the branches to consider possible causes of power fluctuation and add detail to their part of the fishbone diagram, as shown in Figure 14.6 Possible Causes of Power Fluctuation . Check sheets, histograms, and Pareto charts are used to solve several quality problems. When a quality-control issue occurs, a project manager must choose which problem to address first. One way to prioritize quality problems is to determine which ones occur most frequently. These data can be collected using a check sheet, which is a basic form on which the user can make a check in the appropriate box each time a problem occurs or by automating the data collection process using the appropriate technology. Once the data are collected, they can be analyzed by creating a type of frequency distribution chart called a histogram. A true histogram is a column chart where the widths of the columns fill the available space on the x-axis axis and are proportional to the category values displayed on that axis, while the height of the columns is proportional to the frequency of occurrences. Most histograms use one width of column to represent a category, while the vertical axis represents the frequency of occurrences.
A variation on the histogram is a frequency distribution chart invented by economist Vilfredo Pareto known as a Pareto chart, in which the columns are arranged in decreasing order with the most common on the left and a line added that shows the cumulative total. The combination of columns and a line allows the user to tell at a glance which problems are most frequent and what fraction of the total they represent.
Once you have your quality plan, you know your guidelines for managing quality on the project. Your strategies for monitoring project quality should be included in the plan, as well as the reasons for all the steps you are taking. It’s important that everyone on the team understand the rationale behind the metrics being used to judge success or failure of the project.
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